A balance doesn't intrinsically "know" what a gram is. Over time, its internal sensors can drift due to environmental changes, wear, or even being moved, causing readings to become inaccurate. Calibration addresses this by essentially 're-teaching' the balance, ensuring its readings are accurate and reliable.
Analytical Balances – For very high precision, measuring down to 0.1 mg (0.0001 g) or even 0.01 mg (0.00001 g). They typically include an enclosed draft shield to protect against air currents.
Precision Balances (Top-Loading Balances) – Offer good precision, typically measuring down to 0.01 g or 0.001 g. They are faster and more convenient for weighing larger samples, making them ideal for general lab use.
| Feature | Analytical Balance | Precision Balance |
| Accuracy | Ultra-high(0.0001g) | Moderate(0.001g) |
| Sensitivity | Detects minute mass changes | suitable for larger samples |
| Weighing Capacity | Up to 500g | Up to several kilograms |
| Draft Shield | Yes | Usually No |
| Cost | Higher | More afforable |
| Weights used for daily inspection | Class F1 | Class F2 |
| Weights used for Calibrating Balances | Class E2 | Class F1 |
E1 & E2 Weights: The highest precision, used for calibrating analytical and semi-micro balances.
F1 & F2 Weights: High precision for analytical and precision balances.
M1 Weights: More common for general industrial and bench scales.
Weight serves as a known, traceable standard to define and verify the accuracy of a balance's measurements. Calibration establishes a precise relationship between the weight's certified mass and the balance's electronic or mechanical output.
